How_Solar_Works_MassCECRooftop solar: power your home with clean energy (courtesy Mass Clean Energy Center)

Installing solar panels on your roof can take advantage of two great resources: free and abundant sunlight, and generous financial incentives. Not every roof is a good candidate for solar power, but many are. Solar power can reduce your utility bills and make your home more climate friendly by reducing the amount of power that needs to be generated at polluting power plants. If you also install a backup battery, you can power your home at night and during power outages.

There are two types of rooftop solar panels: photovoltaic and solar hot water.

Photovoltaic (PV). Solar PV generates electricity for use in a home or other building, with excess electricity sold back to to the utility (Eversource). There are two basic ownership models: own and lease. Ownership is straightforward: you purchase the panels and pay off your investment with tax incentives and energy savings. Under a lease model (sometimes called a power purchase agreement, or PPA), a private company purchases and owns the solar panels and homeowners generally pay for the electricity, albeit at a generally lower cost than purchasing electricity from the utility.

There are many solar companies to choose from, and we recommend that you get multiple quotes. One useful tool for obtaining solar PV installation quotes (for solar panels you own, not lease) is EnergySage. The EnergySage website is easy to use and generates multiple solar installer quotes for you to choose from. 

Another solar PV model is community solar. Community solar can be a good alternative to rooftop solar when a roof is shaded or otherwise unsuitable to host solar panels. Community solar projects are large solar installations that multiple individuals, companies and even municipalities can purchase a share in.  There are no community solar farms located in Winchester, but Winchester residents and businesses can sign up to purchase power from community solar projects located elsewhere. The Mass Clean Energy Center hosts an excellent community solar website.

Solar hot water. These systems generate domestic hot water for use in showers, sinks, washing machines, etc. They do not generate electricity, although it is often possible to locate both solar hot water and PV panels on the same roof. Solar hot water systems are highly efficient, and with a suitably-sized storage tank water heated on one day is plenty hot for morning showers the next day.  These systems tend to be much more affordable to install than solar PV, and benefit from generous financial incentives (see below). The Mass Clean Energy Center hosts an excellent solar hot water website.

Financial Incentives. Generous financial incentives exist for both solar PV and solar hot water systems. Purchase of either type of system is eligible for up to 26 percent (dropping to 22 percent on 1/1/2023) federal tax credit - click here for more details (this credit is currently scheduled to expire on 12/31/2023). There is also a $1,000 Mass. personal income tax credit. The Solar Massachusetts Renewable Target (SMART) program, which is run by the electric utilities, offers monthly incentive payments for solar production that last ten years. Finally, owners of solar PV systems can sell excess power generation to the utilities at a favorable rate thanks to the Massachusetts Net Metering program. Many solar installers are familiar with solar incentive programs and can help customers fill out the right paperwork.

Additional Resources

Mass Clean Energy Center solar website - lots of useful information about solar power, financing mechanisms and financial incentives.

The Mass Clean Energy Center's Clean Energy Lives Here website also contains extremely useful information about solar PV and solar hot water.